THE SCAVENGER OF THE OCEAN. 229 



small animals are sometimes found made by them in ponds. 

 Tadpoles will eat up a dead kitten, and will also condescend 

 to decayed vegetable matter, but when other food fails they 

 turn cannibals and prey upon one another. 



Among the lesser fresh-water scavengers are certain 

 little long, narrow worms, with which dead, and even sickly 

 fishes are often found to be covered. 



But to return to the crustaceans, among which the common 

 shrimp (Fig. 48) is pre-eminent as a "capital skeleton- 



Fig. 48. THE COMMON BROWN SHRIMP. 



maker." So voracious is he that he is called, par excellence^ 

 the "scavenger of the ocean," but the crab, both in water and 

 on land is an equally diligent consumer of dead animals ; 

 and among crabs one of the most useful is the Thorn-back 

 Spider-crab, which, though he does good service in the 

 sea, is more especially useful along the coast, thanks to 

 his large appetite and the keen sense which guides him 

 unerringly to his food. But for his labours the sea-shore 

 would often be anything but a charming recreation ground, 

 for the sands would be strewn with the dead bodies of 



